Linear dampers are devices designed to provide absorption of shock and smooth deceleration in linear motion applications. Dampers provide shock absorption through the application of a damping force in the direction of the linear motion. Dampers may generate the damping force from a variety of means. Dampers may be mechanical (e.g., elastomeric or wire rope isolators), fluid (e.g. gas, air, hydraulic), or even magnetic (e.g. through magnetically induced eddy currents).
Fluid dampers (i.e. hydraulic dampers) depend on the viscosity of a fluid to absorb or dissipate kinetic energy generated by relative motion. Hydraulic dampers allow the fluid to absorb the shock of motion by controlled fluid flow between chambers of a cylinder during piston actuation. Frictionless hydraulic dampers (i.e. without the use of cylinders/pistons) are desired for certain applications to attenuate forces between relatively movable objects where the internal frictional resistance of the dampers is objectionable due to wear and static friction. An exemplary frictionless hydraulic damper is disclosed in U.S. Pat. No. 4,815,574 to Taylor et al, which is included herein by reference.
Magnetic dampers provide a linear damping element in a compact form. Magnetic dampers do not suffer from certain problems associated with hydraulic dampers including friction or leaking of fluids. Additionally, magnetic dampers can operate more consistently over wider temperature ranges than fluidic dampers. However, when not used at cryogenic temperatures magnetic dampers can be relatively heavy.